Commercial food service establishments, such as restaurants, produce considerable amounts of organic material in their waste or drainage water which often includes high levels of grease or oil. Such materials can clog or adversely affect public wastewater and sewer systems. Most jurisdictions therefore require that such grease and oil be removed from the wastewater at the commercial establishment before it is permitted to enter the wastewater system.
To effect such removal, the commercial establishment will typically install a grease interceptor on its wastewater outlet line from its food preparation area, such as its kitchen. The purpose of the grease interceptor is to permit the free flow of wastewater, while capturing any grease or oils contained in the water. The process of grease interception involves the separating and retaining of globules of grease, fats and oils from wastewater as it passes through the grease interceptor. Typically the oily wastewater passes into the grease interceptor at one end and as the water flows through the interceptor it is slowed down, allowing the lighter than water components, such as grease and oil, to rise within the water accumulating in an upper layer in the interceptor. A fluid outlet from the grease interceptor is positioned below the level of the grease layer to permit substantially grease free wastewater to pass through the interceptor. In this way, the grease is collected in the grease interceptor and it may be periodically removed from the top of the grease interceptor. The grease is then disposed of as solid waste in accordance with local regulations, for example, by removal to landfill sites.
Grease interceptors are typically installed below grade and in line with wastewater outlet or effluent pipes. The distance between the finished grade and the top of the grease interceptor will typically vary depending on the distance of the grease interceptor from the building, the slope of the land, and other factors. Accordingly, the distance between the top of the grease interceptor and the finished grade may vary widely between installations. As a result, there is a need for an adjustable height lid.